1. Field of the Invention
The present invention relates to printed circuit boards on which one or more electronic components are interconnected by means of printed conductors on the circuit board.
2. Description of the Prior Art
In the assembly of electronic circuit boards on which a number of electronic components are to be mounted, it is customary, particularly for communications apparatus, to pre-combine a number of components into a unitary network such as a resistance network, a capacitance network or an RC network, or hybrids thereof. Such networks are conventionally mounted on the upper components side of the printed circuit board. Generally, resistance networks are manufactured by means of vapor-depositing or imprinting of resistance layers on relatively thin substrates. This method generates a favorable resistance network, however, the network so produced occupies a relatively large area when installed on the printed circuit board.
Such resistance networks are generally equipped with component legs and require a large number of connection locations for electrical and mechanical contact with the circuit board. Equipping conventional resistance networks further adds to the expense of manufacture of such networks. The connection of the resistance layers to the legs which form the component leads generally is undertaken by soldering one appropriately shaped end of the lead to a particular resistance layer. The lead wires are then, if necessary bent 90.degree. for "dual-in-line" insertion, and are inserted into the soldering lugs on the upper side of a printed circuit board. The component legs are then electrically connected to the board, for example, by dip soldering.
It is known from an article by Klasche in "Elektronik", 1979 Vol. 19, pp. 52-65 to mount components in chip-form on the soldering side of a circuit board. As disclosed in the article, however, such a mounting technique is for use with an entirely new printed circuit board technology, rather than with conventional circuit boards.